title: Whitening effect of Sophora flavescens extract.
abstract: BACKGROUND
  Sophora flavescens Ait. (Leguminosae) has been proposed as a new whitening agent for cosmetics, because it has a strong ability to inhibit tyrosinase, a key enzyme in the formation of melanin.
  
  
  OBJECTIVE
  We conducted a study to determine whether ethanol extract of the roots of S. flavescens has the potential for use as a whitening cosmetic agent by investigating its underlying mechanisms of action.
  
  
  METHODS
  To elucidate the mechanism of action of S. flavescens extract, we used DNA microarray technology. We investigated the changes in the mRNA levels of genes associated with the formation and transport of melanosomes. We also identified the formation and transport of melanosomes with immunohistochemistry and immunofluorescence analyses. Finally, the skin-whitening effect in vivo of S. flavescens extract was analyzed on human skin.
  
  
  RESULTS
  We found that S. flavescens extract strongly inhibited tyrosinase activity (IC50, 10.4 μg/mL). Results also showed that key proteins involved in the formation and transport of melanosomes were dramatically downregulated at both mRNA and protein level in keratinocytes exposed to S. flavescens extract. In addition, a clinical trial of a cream containing 0.05% S. flavescens extract on human skin showed it had a significant effect on skin whitening by mechanical and visual evaluation (1.14-fold).
  
  
  CONCLUSIONS
  This study provides important clues toward understanding the effects of S. flavescens extract on the formation and transport of melanosomes. From these results, we suggest that naturally occurring S. flavescens extract might be useful as a new whitening agent in cosmetics.
authors.affiliation: R&D Center, Somang Cosmetics Corporation , Namdong-gu, Incheon , Republic of Korea .
authors.forename: Dae Hyun
authors.initials: DH
authors.lastname: Shin
authors.forename: Youn Jeong
authors.initials: YJ
authors.lastname: Cha
authors.forename: Gi Jung
authors.initials: GJ
authors.lastname: Joe
authors.forename: Kyeong Eun
authors.initials: KE
authors.lastname: Yang
authors.forename: Ik-Soon
authors.initials: IS
authors.lastname: Jang
authors.forename: Bo Hyeon
authors.initials: BH
authors.lastname: Kim
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Kim
mesh_terms: D000328:Adult; D002460:Cell Line; D018920:Coculture Techniques; D004311:Double-Blind Method; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects / Q000378:metabolism; D020460:Melanosomes / Q000187:drug effects* / Q000378:metabolism; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D018517:Plant Roots; D010946:Plants, Medicinal; D012333:RNA, Messenger / Q000378:metabolism; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D062327:Skin Lightening Preparations / Q000494:pharmacology*; D012880:Skin Pigmentation / Q000187:drug effects* / Q000235:genetics; D029909:Sophora; D055815:Young Adult
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D012333:RNA, Messenger; D062327:Skin Lightening Preparations; D014442:Monophenol Monooxygenase